I suggest you...

Allow time in filters to be specified as "yesterday," "today," & "tomorrow" so that Smart Filters do not have to be updated

Right now date filters in Smart Views have to be absolute dates or references to differences from absolute dates. You can't have a date filter that says "Start Date is before TOMORROW" and have the date filter automatically change as time progresses. But you can in ToodleDo in a Saved Search (ToodleDo's equivalent of a Smart View). ToodleDo is smart enough to deal with absolute date references, same as 2Day, and also relative date references to whatever date "TOMORROW" happens to be right now. 2Day would be a lot more useful if it were clever enough to allow such relative references and it would save the user a lot of time updating absolute date references in Smart View filters.

You do have specific indirect references to Today, Tomorrow, and Yesterday but what you don't have is "is before Tomorrow," "is after Today," "less than 7 days from now," etc. These indirect time references are very useful to MYN (Managing Your Now). "Is Today, Tomorrow, or Was Yesterday" just don't cut it.